Issue when using multi-stage build together with injectRestartHelper

[timo-klarshift]

What happened?
I changed my image to use a multi-stage build. Using plain docker to build the image works, but using devspace to build the image it fails. Using injectRestartHelper=false works.

❯ devspace build --force-build
[info]   Building image 'app-proxy:6e0seJO' with engine 'docker'
[+] Building 0.0s (0/1)                                                                                               
[+] Building 1.8s (6/6) FINISHED                                                                                      
 => [internal] load remote build context                                                                         0.0s
 => copy /context /                                                                                              0.1s
 => resolve image config for docker.io/docker/dockerfile:1.0-experimental                                        1.0s
 => CACHED docker-image://docker.io/docker/dockerfile:1.0-experimental@sha256:cbd6491240cc8894d25e366ba83da19df  0.0s
 => CACHED [internal] helper image for file operations                                                           0.0s
 => ERROR [internal] extracting build context                                                                    0.4s
------                                                                                                                
 > [internal] extracting build context:                                                                               
#6 0.365 2020/09/25 12:09:08 exec /usr/bin/tar [tar -xvf /src/context -C /out/]                                       
#6 0.366 .dockerignore                                                                                                
<MANY FILES>
#6 0.370 yarn.lock
#6 0.370 tar: Removing leading `/' from member names
#6 0.370 /.devspace/.devspace
#6 0.370 /.devspace/.devspace/devspace-restart-helper
#6 0.370 tar: Unexpected EOF in archive
#6 0.370 tar: Unexpected EOF in archive
#6 0.370 tar: Error is not recoverable: exiting now
#6 0.372 panic: exit status 2
#6 0.372 
#6 0.372 goroutine 1 [running]:
#6 0.372 main.main()
#6 0.372 	/go/src/github.com/tonistiigi/copy/cmd/copy/main.go:57 +0x2af
------
failed to solve with frontend dockerfile.v0: failed to solve with frontend gateway.v0: rpc error: code = Unknown desc = failed to resolve dockerfile: rpc error: code = Unknown desc = failed to build LLB: executor failed running [copy --unpack /src/context /out/]: runc did not terminate sucessfully
[fatal]  build images: Error during image build: exit status 1

What did you expect to happen instead?
Not to fail when using injectRestartHelper=true and multi-stage build

How can we reproduce the bug? (as minimally and precisely as possible)

Any dummy package.json in $(pwd) is enough to reproduce for this Dockerfile.
I am pretty sure its due to this part somehow:

RUN \
  --mount=type=secret,id=npm,target=/app/.npmrc \  
  yarn --pure-lockfile

test.Dockerfile

# syntax = docker/dockerfile:1.0-experimental

# --- dependencies
FROM node:14-alpine as build-deps

WORKDIR /app
COPY package.json yarn.lock ./
RUN \
  --mount=type=secret,id=npm,target=/app/.npmrc \  
  yarn --pure-lockfile

# --- build app
FROM node:14-alpine as app
COPY --from=build-deps /app/node_modules /app/node_modules

USER node

ENTRYPOINT [ "docker-entrypoint.sh" ]
CMD ["npm", "run", "start:proxy"]

images:
  app:
    image: app
    preferSyncOverRebuild: true
    injectRestartHelper: true
    dockerfile: ./test.Dockerfile
    build:
      docker:
        useBuildKit: true
        skipPush: true
        options:
          target: app
        args:
          - '--secret'
          - 'id=npm,src=${USER}/.npmrc'

Local Environment:
devspace version 5.0.3
Docker version 19.03.12-ce, build 48a66213fe
linux
helm

Kubernetes Cluster:
not relevant, its just about image build

Anything else we need to know?

/kind bug

[timo-klarshift]

@LukasGentele It seems I fixed it:

Following the error produced by my issue, I ended up here: moby/buildkit#958

By changing
# syntax = docker/dockerfile:1.0-experimental
to
# syntax = docker/dockerfile:1.1-experimental

I think this can be closed. I am not sure exactly what is happening under the hood. AFAIK no symlinks are used in my setup. Maybe its worth mentioning somewhere. Also where can I find released/available buildkit versions for Dockerfile? Does anybody know ?

[timo-klarshift]

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